Why not angular 3?
Because they wanted to sync the angular version with the angular router version. Angular will have a new version release every six months but Angular 4 will be backward compatible with Angular 2 Angular is being developed in a MonoRepo it means a single repo for everything. @angular/core , @angular/compiler , @angular/router, etc are in the same repo and may have their own versions. The advantage of MonoRepo is, you don’t have to deal with the versioning of the code dependencies. Now the problem is with the @angular/router which is already in a 3. X version. And that’s because of some active and huge developments on the router section, like route-preload. Now releasing Angular as version 3, with its route on version 4 will create confusion To avoid this confusion they decided to skip version 3 and release version 4.0.0, so that every major dependency in the MonoRepo is on the right track. ref: http://blog.angularjs.org/2016/12/ok-let-me-explain-its-going-to-be.html#Why_not_versi...